The field of the invention is air cargo containers.
Air cargo containers have been used for the transportation of cargo by aircraft for many years. Cargo such as cartons, smaller shipping containers, etc. are loaded into the containers. The containers are then loaded into an aircraft. Use of air cargo containers is much faster than loading cargo directly into the cargo space of the aircraft because the individual cartons need not be separately placed and secured within the aircraft. The air cargo containers can also be loaded at locations remote from the airport. Furthermore, because the cargo containers are typically designed and constructed to correspond to the interior dimensions of the aircraft cargo space, the containers fit more securely in the cargo space and do not shift during flight. These and other advantages of air cargo containers have made air cargo containers widely used in the air freight and airline industry.
New fuel efficient cargo aircraft are designed to carry so-called “high cube” cargo containers. These containers are containers are taller than standard cargo containers, with high cube containers typically 88, 96, 108, or 118 inches tall. Cargo personnel typically have difficulty loading and unloading packages into the top areas of high cube containers, especially at heights greater than about than 88 inches. On the other hand, if the cargo container can be filled with cargo up to its full height, the load density of the container is maximized. Since the load capacity of the aircraft is generally limited by cargo volume and not by weight, completely filling the air cargo containers allows the aircraft to carry more cargo, since empty space in the cargo containers is minimized.
While ladders or step stools allow cargo allow cargo personnel to reach the upper areas of the cargo containers, they have not been widely used. One disadvantage with use of a ladder is that the ladder may not be conveniently available, since it is removed from the air cargo container after each use. Another factor is that a ladder may not always be stable, especially when the floor of air cargo container is uneven, due to built in design elements, such as structural channel sections, fasteners and tie downs projecting up from the floor, or due to in-use wear, deformation, or damage to the floor.
Accordingly, engineering challenges remain in designing an air cargo container that allows cargo loading personnel to readily reach and place packages in upper areas of air containers.